ACCF/AHA/ACR/SCAI/SIR/SVM/SVN/SVS 2010 Performance Measures for Adults With Peripheral Artery Disease
A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Performance Measures, the American College of Radiology, the Society for Cardiac Angiography and Interventions, the Society for Interventional Radiology, the Society for Vascular Medicine, the Society for Vascular Nursing, and the Society for Vascular Surgery (Writing Committee to Develop Clinical Performance Measures for Peripheral Artery Disease)
- AHA Scientific Statements
- abdominal aortic aneurysm
- ankle brachial index
- peripheral arterial disease
- secondary prevention
- supervised exercise
Over the past decade, there has been an increasing awareness that the quality of medical care delivered in the United States is variable. In its seminal document dedicated to characterizing deficiencies in delivering effective, timely, safe, equitable, efficient, and patient-centered medical care, the Institute of Medicine described a quality “chasm”.1 Recognition of the magnitude of the gap between the care that is delivered and the care that ought to be provided has stimulated interest in the development of measures of quality of care and the use of such measures for the purposes of quality improvement and accountability.
Consistent with this national focus on healthcare quality, the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) have taken a leadership role in developing measures of the quality of care for cardiovascular disease (CVD) in several clinical areas (Table 1). The ACCF/AHA Task Force on Performance Measures was formed in February 2000 and was charged with identifying the clinical topics appropriate for the development of performance measures and with assembling writing committees composed of clinical and methodological experts. When appropriate, these committees have included representation from other organizations involved in the care of patients with the condition of focus. The committees are informed about the methodology of performance measure development and are instructed to construct measures for use both prospectively and retrospectively, to rely upon easily documented clinical criteria, and where appropriate, to incorporate administrative data. The data elements required for the performance measures are linked to existing ACCF/AHA clinical data standards to encourage uniform measurements of cardiovascular care. The writing committees are also instructed to evaluate the extent to which existing nationally recognized performance measures conform to the attributes of performance measures described by the ACCF/AHA and to strive to create measures aligned with acceptable existing measures when this is feasible.
The initial measure sets published by the ACCF/AHA focused primarily on processes of medical care, or actions taken by healthcare providers, such as the prescription of a medication for a condition. These process measures are founded on the strongest recommendations contained in the ACCF/AHA clinical practice guidelines, delineating actions taken by clinicians in the care of patients, such as the prescription of a particular drug for a specific condition. Specifically, the writing committees consider as candidates for measures those processes of care that are recommended by the guidelines either as Class I, which identifies procedures and/or treatments that should be administered, or Class III, which identifies procedures and/or treatments that should not be administered (Table 2). Class II recommendations are not considered as candidates for performance measures. The methodology guiding the translation of guideline recommendations into process measures has been explicitly delineated by the ACCF/AHA, providing guidance to the writing committees.10
Although they possess several strengths, processes of care are limited as the sole measures of quality. Thus, current ACCF/AHA Performance Measures writing committees are instructed to consider measures of structures of care, outcomes, and efficiency as complements to process measures. In developing such measures, the committees are guided by methodology established by the ACCF/AHA.11 Although implementation of measures of outcomes and efficiency is currently not as well established as that of process measures, it is expected that such measures will become more pervasive over time.
Although the focus of the performance measures writing committees is on measures intended for quality improvement efforts, other organizations may use these measures for external review or public reporting of provider performance. Therefore, it is within the scope of the writing committee's task to comment, when appropriate, on the strengths and limitations of such external reporting for a particular CVD state or patient population. Thus, the metrics contained within this document are categorized as either performance measures or test measures. Performance measures are those metrics that the committee designates as appropriate for use for both quality improvement and external reporting. In contrast, test measures are those appropriate for the purposes of quality improvement but not for external reporting until further validation and testing are performed.
All measures have limitations and pose challenges to implementation that could result in unintended consequences when used for accountability. The implementation of measures for purposes other than quality improvement requires field testing to address issues related but not limited to sample size, frequency of use of an intervention, comparability, and audit requirements. The manner in which these issues are addressed is dependent on several factors, including the method of data collection, performance attribution, baseline performance rates, incentives, and public reporting methods. The ACCF/AHA encourages those interested in implementing these measures for purposes beyond quality improvement to work with the ACCF/AHA to consider these complex issues in pilot implementation projects, to assess limitations and confounding factors, and to guide refinements of the measures to enhance their utility for these additional purposes.
By facilitating measurements of cardiovascular healthcare quality, ACCF/AHA performance measurement sets may serve as vehicles to accelerate appropriate translation of scientific evidence into clinical practice. These documents are intended to provide practitioners and institutions that deliver care with tools to measure the quality of their care and identify opportunities for improvement. It is our hope that application of these performance measures will provide a mechanism through which the quality of medical care can be measured and improved.
The ACCF/AHA/ACR/SCAI/SIR/SVM/SVN/SVS Peripheral Artery Disease Performance Measures Writing Committee was charged to develop performance measures for peripheral artery disease (PAD). These performance measures address lower extremity and abdominal aortic disease, as covered by the ACC/AHA 2005 Guidelines for the Management of Patients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic) (hereafter, “PAD guidelines”).12 The measures are intended for adults (age ≥18 years) evaluated in the outpatient setting. The writing committee acknowledges that the field is rapidly evolving due to the contributions of observational research, registries, and clinical trials. Hence, modifications to these performance measures for PAD will be necessary as the field advances. In addition, there has been a recent change in the nomenclature for vascular diseases.13 The term atherosclerotic vascular disease refers to disease of the arteries (other than the coronary arteries) caused by atherosclerosis.14 We have incorporated this new terminology into this document where it is feasible to do so.
1.1. Scope of the Problem
The PAD guidelines12 state that:
the term “peripheral arterial disease” includes a diverse group of disorders that lead to progressive stenosis or occlusion, or aneurysmal dilation, of the aorta and its noncoronary branch arteries, including the carotid, upper extremity, visceral, and lower extremity arterial branches. Peripheral arterial disease is the preferred clinical term that should be used to denote stenotic, occlusive, and aneurysmal diseases of the aorta and its branch arteries, exclusive of the coronary arteries (page e7).
For the purposes of these performance measures, the term peripheral artery disease in the title is used to denote atherosclerotic stenosis or occlusion of the aorta and arteries supplying the lower extremities and abdominal aortic aneurysms (AAAs).13,14
PAD is a marker of systemic atherosclerosis. It has been estimated that approximately 8 million persons in the United States are afflicted with PAD.15 The prevalence of PAD is approximately 12% of the adult population, with men being affected slightly more than women.16,17 However, this percentage is age dependent. Almost 20% of adults over the age of 70 years have PAD.18 Findings from a national cross-sectional survey of PARTNERS (PAD Awareness, Risk, and Treatment: New Resources for Survival) found that PAD afflicts 29% of patients who are age ≥70 years, age 50 to 69 years with at least a 10–pack-per-year history of smoking, or age 50 to 69 years with a history of diabetes.19 Despite the strikingly high prevalence of PAD, this disease is underdiagnosed because it often presents with atypical symptoms or no ischemic symptoms related to the legs at all. More than 70% of primary care providers in the PARTNERS study whose patients were screened were unaware of the presence of PAD in those with the disease.19
The clinical presentation of PAD may vary from no symptoms to intermittent claudication, atypical leg pain, rest pain, ischemic ulcers, or gangrene. Claudication is the typical symptomatic expression of PAD. However, asymptomatic disease may occur in up to 50% of all patients with PAD.12 The Walking and Leg Circulation Study evaluated the symptoms in patients with PAD. Of the 460 patients with PAD, 19.8% had no exertional leg pain, 28.5% had atypical leg pain, 32.6% had classic intermittent claudication, and 19.1% had pain at rest.20 The results of these and other studies make it readily apparent that more patients with PAD are asymptomatic or have atypical leg symptoms than have classic intermittent claudication.
PAD has 2 major consequences: The first is a decrease in overall well-being and quality of life due to claudication and atypical leg pain.21,–,25 This often leads to patients becoming sedentary and limiting the amount of walking they do because of pain and discomfort. This may be associated with depression.26 The second is a markedly increased cardiovascular morbidity (myocardial infarction and stroke) and mortality (cardiovascular and all-cause). Treatment should be directed at each of these facets.
PAD is most often diagnosed by an ankle-brachial index (ABI) ≤0.9. A low ABI is an independent predictor of increased mortality.27,–,32 In the Framingham Study, mortality in patients with intermittent claudication was 2–3 times higher than in age- and sex-matched control patients, with 75% of PAD patients dying from cardiovascular events. In a 15-year review of patients with claudication, over 66% of mortality was attributable to CVD.17 In a 10-year prospective study by Criqui et al,33 PAD patients both with and without a history of CVD had significantly increased risk of dying from cardiovascular and coronary heart disease compared with age-matched control patients. The all-cause mortality was 3.1 times greater and the CVD mortality was 5.9 times greater in patients with PAD compared with patients without PAD. The risk of cardiovascular events has been found to be similar between PAD patients with claudication and PAD patients without symptoms.34 The extremely high morbidity and mortality in the PAD population is due to myocardial infarction and stroke.35,36 Both the Edinburgh Artery Study and the ARIC (Atherosclerosis Risk in Communities) study correlated an increased risk of stroke and transient ischemic attack with increased PAD severity.34,37 The combination of known coronary or cerebrovascular disease with PAD has been shown to increase mortality risk. The BARI (Bypass Angioplasty Revascularization Investigation) trial demonstrated that patients with multivessel coronary artery disease (CAD) and PAD had a 4.9 times greater relative risk of death compared with those individuals without PAD.38 In addition, in a pooled analysis of 8 randomized prospective trials involving 19,867 patients undergoing percutaneous coronary intervention, the 1-year mortality was 5% in patients with PAD and coronary disease compared with 2.1% in patients with coronary disease alone (P<0.001).39
Despite the overwhelming evidence that patients with PAD are at a markedly increased risk of myocardial infarction, stroke, and death, these patients are often undertreated, in that they do not receive antiplatelet therapy or statins with the same frequency as do patients with coronary artery disease.19
Thus, these PAD performance measures are directed at strategies to improve diagnosis and treatment of patients with PAD with an overall goal of improving patients' walking distance and speed, improving their quality of life, and decreasing cardiovascular event rates.
1.2. Structure and Membership of the Writing Committee
The members of the writing committee included experienced clinicians and specialists in vascular medicine, cardiology, vascular surgery, exercise physiology, vascular and interventional radiology, interventional cardiology, endocrinology, and epidemiology. The writing committee also included representatives from the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR); the American College of Physicians (ACP); the American College of Radiology (ACR); the American Diabetes Association (ADA); the National Heart, Lung, and Blood Institute (NHLBI); the PAD Coalition; the Society for Atherosclerosis Imaging and Prevention (SAIP); the Society for Cardiac Angiography and Interventions (SCAI); the Society of Cardiovascular Computed Tomography (SCCT); the Society for Cardiovascular Magnetic Resonance (SCMR); the Society for Interventional Radiology (SIR); the Society for Vascular Medicine (SVM); the Society for Vascular Nursing (SVN); and the Society for Vascular Surgery (SVS).
1.3. Disclosure of Relationships With Industry
The work of the writing committee was supported exclusively by the ACCF and AHA. Committee members volunteered their time, and there was no commercial support for the development of these performance measures. Meetings of the writing committee were confidential and attended only by committee members and staff. Writing committee members were required to disclose in writing all financial relationships with industry relevant to this topic according to standard ACCF and AHA reporting policies and verbally acknowledged these relationships to the other members at each meeting (see Appendix A). A confidential final vote was conducted on each measure proposed for inclusion in this set. Committee members with relationships relevant to a specific measure did not participate in the voting regarding that measure but were allowed to participate in the discussion after disclosing the relationship. In addition, Appendix B includes relevant relationships with industry information for all peer reviewers of this document.
1.4. Review and Endorsement
Between July 20, 2009, and August 18, 2009, this performance measure document underwent a 30-day public comment period, during which ACCF and AHA members and other health professionals had an opportunity to review and comment on the text in advance of its final approval and publication. Sixteen public responses were received.
The official peer and content review of the document was conducted simultaneously with the 30-day public comment period, with 2 peer reviewers nominated by the ACCF, 2 nominated by the AHA, and 2 peer reviewers nominated by each of the other partnering organizations (ACR, SCAI, SIR, SVM, SVN, and SVS) and by each collaborating organization (AACVPR, ADA, PAD Coalition, SAIP, SCCT, and SCMR). Additional comments were sought from clinical content experts and performance measurement experts, and 8 individual content reviewer responses were received. All peer and content reviewer relationships with industry information was collected and distributed to the writing committee and is published in this document. (See Appendix B for details.)
The ACCF/AHA/ACR/SCAI/SIR/SVM/SVN/SVS 2010 Performance Measures for Adults With Peripheral Artery Disease was adopted by the respective Boards of Directors of the ACCF and AHA in August 2010. These measures will be reviewed for currency once annually and updated as needed. They should be considered valid until either updated or rescinded by the ACCF/AHA Task Force on Performance Measures.
The development of performance systems involves identification of a set of measures targeting a specific patient population observed over a particular time period. To achieve this goal, the ACCF/AHA Task Force on Performance Measures has outlined 5 mandatory sequential steps. Sections 2.1 through 2.5 outline how the writing committee addressed these elements.
2.1. Target Population and Care Period
The target population consists of patients age ≥18 years. The writing committee developed exclusion criteria specific to each measure to further specify the target population.
2.2. Dimensions of Care
Given the multiple potential domains of treatment that can be measured, the writing committee identified the relevant dimensions of care that should be evaluated. We placed each potential performance measure into the relevant dimension of care categories. Performance measures and test measures selected for inclusion in the final set and their dimensions of care are summarized in Table 3. Appendix C provides the detailed specifications for each measure.
Although the writing committee considered a number of additional measures that focus on equally important aspects of care, length and complexity considerations did not allow their inclusion in the set. Some of the reasons for this are discussed later in this paper.
2.3. Literature Review
The writing committee used the PAD guidelines as the primary source for deriving these measures.12 In addition, the writing committee also reviewed guidelines in “Transatlantic Inter-Societal Consensus for the Management of Peripheral Arterial Disease (TASC II)”40 and the “AACVPR/ACC/AHA 2007 Performance Measures on Cardiac Rehabilitation for Referral to and Delivery of Cardiac Rehabilitation/Secondary Prevention Services”.7
2.4. Definition of Potential Measures
Explicit criteria exist for the development of performance measures that accurately reflect quality of care. These criteria include: 1) defining the numerators and denominators of potential measures, and 2) evaluating their applicability, interpretability, and feasibility. To select measures for inclusion in the performance measurement set, the writing committee prioritized the recommendations from the PAD guidelines.12
2.5. Selection of Measures for Inclusion in the Performance Measure Set
From analysis of these recommendations, the writing committee identified potential measures relevant to adults with PAD and then independently evaluated their potential for use as performance measures using 9 exclusion criteria adapted from the ACCF/AHA Attributes of Performance Measures (Table 4) and the Performance Measure Survey Form and Exclusion Criteria Definitions (Appendix D). Member ratings of all the potential measures were collated and discussed by the full committee so that members could reach consensus about which measures should advance for inclusion in the final measure set. There were 37 potential measures initially advanced for full specification to assess their suitability as performance measures. Through an iterative process of repeated surveys within the writing committee, these potential measures were eventually reduced to 7 final performance measures and 2 test measures. After additional discussion and refinement of measure specifications, the writing committee conducted a confidential vote on whether to include each measure and whether to designate any of the measures as test measures in the final set. Writing committee members were required to recuse themselves from voting on any measures for which they had significant relevant relationships with industry.
3. Peripheral Artery Disease Performance Measures
3.1. Definition of Peripheral Artery Disease and Abdominal Aortic Aneurysm
Atherosclerotic vascular disease encompasses a range of noncoronary arterial syndromes that are caused by the altered structure and function of the arteries that supply the brain, visceral organs, and the limbs. Numerous pathophysiologic processes can contribute to the creation of stenosis or aneurysms of the noncoronary arterial circulation, but atherosclerosis remains the most common disease process affecting the aorta and its branch arteries.
3.2. Brief Summary of the Measurement Set
Table 5 summarizes the ACCF/AHA/ACR/SCAI/SIR/SVM/SVN/SVS PAD Performance Measurement Set—those measures with the highest level of evidence and support among the writing committee members. Appendix C provides the detailed specifications for each performance measure, including the numerator, denominator, period of assessment, method of reporting, sources of data, rationale, clinical recommendations, recommended level of attribution and/or aggregation, and challenges to implementation.
3.3. Data Collection
These performance measures for PAD are ideally intended for prospective use to enhance the quality improvement process but may also be applied retrospectively. We recommend use of a data collection instrument to aid compilation (see Appendix E). Individual institutions may modify the sample instrument or develop a different tool based on local practice and standards.
3.4. Exclusion Criteria and Challenges to Implementation
The writing committee added exclusion criteria, recognizing that there are justifiable reasons for not meeting the performance measures. These reasons should be recorded on the data collection form. Documentation of such factors should be encouraged because this will provide data for future research and facilitate in-depth quality improvement in situations in which there are apparent outliers with respect to the number of patients with medical or patient-centered reasons for exclusion.
Challenges to implementation of the measures are discussed, where applicable. In general, the initial challenge facing any measurement effort is inadequate documentation. Discussion of these challenges is not an argument against any individual measure. Rather, it is a cautionary note that draws attention to areas where additional research may enhance the value of the measures.
The performance measures that were chosen fulfilled the criteria, as outlined in Table 4:
They are useful in improving patient outcomes and are based on Class I evidence: interpretable and actionable.
The measure design is precisely defined and valid in face, content, and construct.
The measure can be implemented with reasonable effort and cost and in a reasonable time period.
The writing committee examined all Class I and Class III recommendations from the PAD guidelines and considered only those guideline recommendations that could be translated into measures that met the criteria stated above. Many potential performance measures did not meet these 3 criteria and thus were not included in this set of measures. Reasons for some of these omissions are discussed in section 4.7. In summary, the final selection of performance measures was based on the evidence base for a given measure, the ease and/or complexity of measurement, and whether the measurement was covered in previously published measurement sets.
Assessment of care remains challenging in all areas of medicine but is particularly so in patients with PAD. PAD is underdiagnosed, undertreated, and poorly understood by many practicing clinicians.19 Although the PAD guidelines12 provide a good first step for many clinicians to establish their clinical expertise, continuing research upon which to base future measurement is important, and continuing modification of the guidelines will be necessary to keep up to date with current knowledge and improve patient outcomes.
Potential performance measures for which the challenges to implementation were considered too difficult to overcome were not included in this data set. In general, the requirements for documentation are an important challenge of any measurement effort. The acknowledgment of these challenges is not an argument against measurement. They are listed to make the reader aware of the potential obstacles that may occur in any measurement set.
4.1. Attribution and/or Aggregation
Clinical performance measures are used to assess quality of care provided by individual physicians. Hence, caution must be exercised if several physicians are actively involved at once with a particular episode of care. Given the nature and clinical course of PAD, most patients require longitudinal follow-up by physicians of different specialties. It is likely that the ACCF/AHA/ACR/SCAI/SIR/SVM/SVN/SVS 2010 Performance Measures for Adults With Peripheral Artery Disease will be utilized by the Centers for Medicare and Medicaid Services and other third-party payers to assess each individual physician caring for patients with PAD. Therefore, it is critical that physicians effectively document in the patient's medical records all clinical data necessary for each PAD performance measure. More important is the need for all clinicians who are participating in a patient's care to share this information consistently so that data collection for performance measures attributable to all involved can be readily available. Such information sharing will also improve communication and coordination of care among physicians caring for patients with PAD.
For the first time in an ACCF/AHA performance measure set, attribution and/or aggregation is listed in each measure. Attribution indicates which clinicians and/or practices should report a given measure (ie, all clinicians and/or practices managing patients with CVD versus only vascular specialists). The level of “aggregation” (clinician versus practice) will depend upon the availability of adequate sample sizes to provide stable estimates of performance. Healthcare providers from many different specialties (primary care, internal medicine, cardiovascular medicine, vascular medicine, interventional radiology, vascular surgery, and endocrinology) may care for patients with PAD, yet not all specialists should be responsible for each performance measure. For example, for lower extremity bypass graft surveillance (Performance Measure 6) only vascular specialists should be held accountable. In addition, the writing committee believes it is now beyond the scope of practice to expect vascular surgeons and interventional radiologists to manage cholesterol-lowering medications (Performance Measure 2). However, vascular surgeons and interventional radiologists should communicate with the primary care physician about the use of statin and antiplatelet therapy in patients with PAD and document such communication and medication use in the chart.
4.2. Overlap With Existing National Performance Measure Sets
All individuals with PAD, regardless of symptom status, ABI, or efficacy of revascularization, face as high (or higher) a short-term risk of a morbid or mortal ischemic event (myocardial infarction, stroke, or death) as that suffered by patients with any other CVD12,42 Nevertheless, although the published peer-reviewed evidence base—as documented in the PAD guidelines12—unambiguously documents that impressive risk reductions are achieved by use of proven pharmacological and lifestyle interventions, individuals with PAD in clinical practice are known to less consistently receive these treatments.19,43,–,45 Furthermore, physicians often do not recognize the cardiovascular risk of PAD. This is a major reason that they do not consistently prescribe such risk-reduction medications for patients with PAD, as they do for individuals with coronary artery disease.46,47 These facts are evident even though other cardiovascular treatment guidelines for lipid lowering, hypertension, and smoking have long included PAD as a “very high risk” patient cohort.
These PAD performance measures therefore provide a critical disease-based opportunity to improve PAD clinical care and outcomes, which can be accomplished only if the use of risk-reduction interventions are measured (as they have been for acute coronary syndromes and heart failure) and thus permit incremental improvement to be systematically achieved.
One measure would evaluate use of statin therapy for lowering lipoprotein cholesterol (LDL-C) in patients with PAD by measuring the fraction of eligible patients with PAD who were prescribed a statin and whose LDL-C is <100 mg/dL. The second measure would evaluate the use of smoking-cessation interventions for active smoking in patients with PAD by documenting the fraction of patients with PAD identified as current smokers who have received smoking-cessation intervention. The third measure would evaluate use of antiplatelet therapy to reduce the risk of myocardial infarction, stroke, or cardiovascular death in patients with a history of symptomatic PAD. Each of these measures should be achievable by any physician, advanced practice nurse, practice, or healthcare system that is dedicated to improving health outcomes for individuals with PAD.
4.3. Ankle Brachial Index
Individuals with PAD are at significant risk for cardiovascular ischemic events, including myocardial infarction, stroke, and death.12,48 Epidemiological studies have shown that even asymptomatic patients suffer mortality rates significantly higher than individuals who do not have PAD. PAD can easily be diagnosed with an ABI ≤ 0.9012,27,29,32,33,35 The ABI is measured with a handheld continuous wave Doppler ultrasound device and a blood pressure cuff. The higher systolic pressure measured from either the posterior tibial or dorsalis pedis artery (in each leg) is compared with the higher brachial artery pressure taken from either arm. Diagnosis of PAD provides the physician the opportunity to initiate treatment to reduce cardiovascular risk and therefore decrease morbidity and mortality. This is particularly important for those individuals who have not previously been diagnosed with an atherosclerotic disease.
The ABI is a simple, inexpensive, noninvasive test that can be easily performed in most clinical settings and has a sensitivity of 79% to 95% and a specificity of 95% to 100%.12 Numerous studies have demonstrated that an abnormal ABI correlates with a significantly increased risk of coronary heart disease, stroke, and cardiovascular death. Most recently, a 2008 meta-analysis demonstrated that a low ABI (<0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each Framingham Risk Score category. Including the ABI in cardiovascular risk stratification using the Framingham Risk Score would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women.49 The writing committee recognizes that reimbursement for the ABI in the office setting is incomplete and that requiring an ABI in persons at risk for PAD adds a burden to busy primary care clinicians. Despite this, the weight of the evidence of the utility of the ABI to predict cardiovascular morbidity and mortality and all-cause mortality and to facilitate initiation of treatment to reduce cardiovascular events has led this writing committee to support the measurement of the ABI in patients at risk (see Performance Measure 1 for definition of at risk) for PAD. It is the writing committee's belief that this measure will also be useful in better documenting current practice patterns of physician office evaluation and in identifying potential opportunities for quality improvements for patients with PAD.
4.4 Antiplatelet Therapy
In the PAD guidelines12 and the “Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II)”,40 antiplatelet therapy is recommended for the treatment of patients with PAD. Several documents in the past year have questioned the efficacy of aspirin in patients with asymptomatic PAD.50,51 The role of antiplatelet therapy in asymptomatic patients is addressed in the upcoming ACCF/AHA focused update to the 2005 PAD guidelines; thus, we have included only patients with a history of symptomatic PAD in this performance measure.
4.5 Supervised Exercise
The PAD guidelines recommend supervised exercise to treat patients with PAD who have claudication because of its proven efficacy and safety.12 Any performance measure that is intended to measure the “appropriateness” of care offered to individuals with PAD and claudication would rightly measure the applied use of this treatment care standard.
Nevertheless, the writing committee is aware that, as for many performance measures, real-world barriers exist that limit actual use of a treatment. The efficacy and safety of PAD exercise rehabilitation for the treatment of claudication is a uniformly recommended, evidence-based, consensus-driven therapy that has a Class I (Level of Evidence: A) recommendation in the 2005 PAD guidelines.12 There is currently incomplete reimbursement for, and therefore a lack of broad availability of, supervised exercise programs, which makes this PAD performance measure difficult to carry out. However, the data supporting the ability of supervised exercise to increase walking capability in patients with claudication are so strong52 that we feel including this treatment modality as a performance measure may help to move it into more general use. Another limiting factor for the low use of exercise rehabilitation is the lack of counseling about and prescription of this therapy by many healthcare professionals. The writing committee believes that more patients would choose a trial of exercise, as they do in other rehabilitative therapies (eg, cardiac rehabilitation, pulmonary rehabilitation, and orthopedic rehabilitation), if they were made aware that this is an efficacious treatment option, or if they were prescribed this option, and especially if it were carried out in a supervised setting.
Patients with PAD should be counseled about all of their treatment options in order to engage them fully in the decision-making process about their care. This counseling and discussion of treatment options should include use of supervised exercise, pharmacological management, and/or the various percutaneous or open surgical revascularization techniques. Inasmuch as exercise rehabilitation has not to date been routinely recommended by clinicians, it is impossible to define what percentage of patients would choose supervised exercise as the first-line therapy if they were made aware of this option and if this treatment modality were reimbursed by third-party payers. Thus, the inclusion of supervised exercise in the PAD performance measures will assure the following: 1) that this evidence-based therapeutic modality will be provided as a component of informed decision making about the various treatment strategies for patients with PAD; 2) that data can be collected to evaluate current claudication treatment recommendation practice patterns; and 3) that these data will be able to be tracked over time as PAD rehabilitation programs, and possible insurance reimbursement, become more widely available. A variety of supervised exercise protocols have been published.53 Practices should create individual options for patients that mirror these protocols in physiologic effectiveness.
It should be noted that ongoing advocacy efforts are under way to align future Centers for Medicare and Medicaid Services and other health payer reimbursement to the current PAD guideline evidence base and thus to include reimbursement for PAD exercise rehabilitation programs. It is anticipated that this essential performance measure will permit patients, healthcare providers, and health payers to be able to make incremental improvements that will assure patient access to all proven claudication therapies. Most current cardiac rehabilitation programs, which are broadly available, are poised to provide PAD exercise rehabilitation. This performance measure provides data that can help translate evidence-based PAD knowledge into real-world care improvements.
4.6. Test Measures
Although it is common sense that one should obtain an accurate vascular history and perform a good vascular examination in all patients suspected of having PAD, the writing committee chose to include measures T-1 and T-2 as test measures only. This decision was made because of the desire to limit the number of performance measures to a reasonable number. We also believe that these measures would be difficult and time consuming to track and would require additional resources for monitoring that may not be available. As test measures, their use should be for internal quality improvement programs only. They are not appropriate for other uses, such as pay for performance, physician ranking, or public reporting programs.
4.7. Potential Measures Considered But Not Included in This Set
4.7.1. Lower Extremity Endovascular Revascularization Surveillance
Although there has been some controversy in the literature there have been several good studies (Class I, Level of Evidence: A) demonstrating that surveillance for vein bypass is an effective way to preserve the long-term function of the bypass and to identify and correct problems before the bypass thromboses.54,–,56 There are no such studies available in patients who have undergone endovascular revascularization, yet it makes intuitive sense that if a problem (eg, restenosis) can be identified, the problem may be correctable before the artery occludes. However, the PAD guidelines gave this a Class IIa designation, thus we were unable to include this as a performance or test measure.
4.7.2. Chronic Critical Limb Ischemia and Acute Limb Ischemia
The writing committee considered numerous potential measures that would focus on the surgical as well as endovascular management of patients with chronic and acute limb ischemia. Although the management of chronic and acute limb ischemia is considered extremely important by the writing committee, specific measures were not included in this area for a variety of reasons. One of the important reasons is that the goal of the writing committee was to develop performance measures that would be relevant to as many clinicians and as many patients as possible. Patients with chronic limb ischemia and acute limb ischemia needing surgical or endovascular therapy represent a small minority of all patients with PAD. Furthermore, the clinicians who actively manage these problems represent a small subset of clinicians who manage patients with PAD. As such, the writing committee felt that the scope of any performance measures adopted in these areas would not be relevant to enough patients and clinicians to justify their inclusion.
Another reason for not including measures in these areas is the complexity of any metrics that might be developed to measure the performance of care. These patients present with very complex symptoms, with multiple comorbidities and significant anatomic variations, which render simple metrics impractical. Finally, the level of evidence for establishing specific guidelines and measures in these areas is not sufficiently rigorous to justify specific performance measures for the management of chronic or acute limb ischemia.
4.7.3. Renal and Mesenteric Artery Disease
There are no performance measures related to renal or mesenteric artery disease included in this report. While renal artery disease is a common cardiovascular condition, the PAD guidelines contain no Class I recommendations related to this disease, and no randomized controlled trials of sufficiently high caliber exist to guide clinicians in the optimal management of patients with renal artery disease. In addition, a considerable controversy remains among “experts” as to the most effective therapy to manage this group of patients. Until the results of the CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) trial57 are reported, healthcare providers will continue to manage this group of patients according to their interpretation of the available literature.
Likewise, there is even less scientific information on mesenteric artery disease available, and thus no performance measures were deemed appropriate for this topic.
4.7.4. Exercise Treadmill Testing
Exercise treadmill testing can assist clinicians in the evaluation of the functional status of PAD patients. A decrease in the postexercise ankle pressures can confirm a diagnosis of PAD in symptomatic patients who have a normal ABI at rest. In addition, exercise treadmill testing allows quantification of a patient's baseline and/or postprocedure functional limitation or improvement.
Despite the potential benefits of this procedure, the writing committee agreed both that this measure would be difficult to implement and that there were other measures with higher priority; thus, we decided not to include this measure.
4.7.5. Computed Tomographic Angiography and Magnetic Resonance Angiography
It has been clearly shown that computed tomographic angiography and magnetic resonance angiography are useful imaging strategies to delineate the anatomy and help plan percutaneous and surgical revascularization.12 However, this potential performance measure did not meet the criteria for a good performance measures as outlined in Table 4.
4.7.6. Management of Hypertension and Diabetes
It is very important to control blood pressure and diabetes to goal levels in patients with PAD. Excellent performance measures already exist on the diagnosis and management of hypertension and diabetes mellitus, and the reader is referred to those.4,58,59
4.7.7. Screening for Abdominal Aortic Aneurysm
This was the most difficult measure to exclude. However, the PAD guidelines assigned this only a Class IIa designation. Because only Class I designations are considered for performance measures, screening for abdominal aortic aneurysm was excluded. However, the U.S. Preventive Task Force60 and the Societies for Vascular Medicine and Surgery61 recommend screening for AAA in the following patient populations:
Men age ≥60 years with a history of AAA in a parent or sibling.
Men age 65 to 75 years who have ever smoked >100 cigarettes in their lifetime.
Screening this patient population has been shown to decrease aneurysm-related mortality.61,–,64 A meta-analysis of 4 large randomized prospective controlled trials65 evaluated the midterm (3.5 to 5 years) and long-term (7 to 15 years) results as related to aneurysm-related mortality and total mortality. Heterogeneity between the studies was assessed by the chi-square test. In cases of heterogeneity, random effect models were used. The pooled midterm analysis demonstrated a reduction in AAA-related mortality (odds ratio [OR], 0.56, 95% confidence interval [CI], 0.44 to 0.72). Overall mortality was nonsignificantly reduced (OR, 0.94, 95% CI, 0.86 to 1.02). The long-term results also showed a reduction in AAA-related mortality (OR, 0.47, 95% CI, 0.25 to 0.90) and a significant reduction in overall mortality (OR, 0.94, 95% CI, 0.92 to 0.97). The conclusion of this meta-analysis was that population screening for AAA reduces AAA-related and overall mortality but local differences may influence the cost-effectiveness of screening.
Kim and associates66 showed that the benefit derived at 4 years was maintained at 7 years of follow-up, with a relative risk reduction of aneurysm-related death of 47%. They also showed that there is a substantial cost-benefit to screening, which is estimated on the basis of AAA-related mortality as U.S. $19,500 per life-year gained. The mortality curves diverge at a constant rate after 1 year, and the area between the curves is greater at years 5 to 7 than years 1 to 4. Thus, the cost per life-year gained decreases in the later years.67 Therefore, when the PAD guideline is revised, if screening for AAA becomes a Class I recommendation, creation of an associated performance measure will be considered.
4.7.8. Outcome Measures
The writing committee recognizes that the most interpretable and potentially important performance measures are outcome measures; however, there are a number of significant limitations to their use for provider accountability or public reporting.11 Outcome measures are therefore currently best suited for use as tools to assist providers in understanding their own performance.
Krumholz et al.6 have eloquently described the importance of assessing outcomes in addition to measuring performance on key processes of care, per se:
Although measures focusing on processes of care have substantial appeal as a means of reflecting quality, such measures assess only a small proportion of all of the care delivered and apply to only subsets of the population with a particular condition. Furthermore, while determining whether a particular process of care was delivered, such measures do not convey information on the effectiveness of the process. Finally, although patients presumably care about the processes of care that they receive, this interest reflects an assumption that better processes of care ultimately result in better outcomes. For these reasons, outcomes measures have been proposed as a means of complementing process measurement as a reflection of quality (p. 2054).
A recent multidisciplinary AHA Scientific Statement, which is endorsed by the ACCF, identified 7 attributes of outcomes measures suitable for public reporting.11 These attributes include: 1) a clear and explicit definition of an appropriate patient sample; 2) clinical coherence of model adjustment variables; 3) sufficiently high-quality and timely data; 4) designation of an appropriate reference time before which covariates are derived and after which outcomes are measured; 5) use of an appropriate outcome and a standardized period of outcome assessment; 6) application of an analytical approach that takes into account the multilevel organization of data; and 7) disclosure of the methods used to compare outcomes, including disclosure of performance of risk-adjustment methodology in derivation and validation samples.
While the writing committee recognizes the importance of developing scientifically valid, effective, and useful measures of clinical outcomes for PAD, we are not yet at the point to do so with the data available. Outcome measurements, however, should be considered in future revisions of the PAD performance measures.
American College of Cardiology Foundation
Ralph G. Brindis, MD, MPH, FACC, FSCAI, President John C. Lewin, MD, Chief Executive Officer Charlene May, Senior Director, Clinical Policy and Documents Melanie Shahriary, RN, BSN, Associate Director, Performance Measures and Data Standards Jensen S. Chiu, MHA, Specialist, Clinical Performance Measurement Erin A. Barrett, MPS, Senior Specialist, Clinical Policy and Documents
American Heart Association
Nancy Brown, Chief Executive Officer Rose Marie Robertson, MD, FACC, FAHA, Chief Science Officer Gayle R. Whitman, PhD, RN, FAHA, FAAN, Senior Vice President, Office of Science Operations Dwight Randle, PhD, Science and Medicine Advisor
Developed in Collaboration With the American Association of Cardiovascular and Pulmonary Rehabilitation; the American Diabetes Association; the Society for Atherosclerosis Imaging and Prevention; the Society for Cardiovascular Magnetic Resonance; the Society of Cardiovascular Computed Tomography; and the PAD Coalition
Endorsed by the American Academy of Podiatric Practice Management
†††Immediate Past Task Force Chair.
This document was approved by the American College of Cardiology Board of Trustees in July 2010 and the American Heart Association Science Advisory and Coordinating Committee in August 2010, by the American College of Radiology in August 2010, by the Society for Cardiac Angiography and Interventions in August 2010, by the Society for Interventional Radiology in August 2010, by the Society for Vascular Medicine in August 2010, by the Society for Vascular Nursing in August 2010, and by the Society for Vascular Surgery in August 2010.
The American Heart Association requests that this document be cited as follows: Olin JW, Allie DE, Belkin M, Bonow RO, Casey DE Jr., Creager MA, Gerber TC, Hirsch AT, Jaff MR, Kaufman JA, Lewis CA, Martin ET, Martin LG, Sheehan P, Stewart KJ, Treat-Jacobson D, White CJ, Zheng Z-J. ACCF/AHA/ACR/SCAI/SIR/SVM/SVN/SVS 2010 performance measures for adults with peripheral artery disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Performance Measures, the American College of Radiology, the Society for Cardiac Angiography and Interventions, the Society for Interventional Radiology, the Society for Vascular Medicine, the Society for Vascular Nursing, and the Society for Vascular Surgery (Writing Committee to Develop Performance Measures for Peripheral Artery Disease). Circulation. 2010;122:2583–2618.
This article has been copublished in Journal of the American College of Cardiology, the Journal of Vascular Nursing, the Journal of Vascular Surgery, and the Vascular Medicine Journal.
Copies: This document is available on the World Wide Web sites of the American College of Cardiology (www.cardiosource.org) and the American Heart Association (my.americanheart.org). A copy of the document is also available at http://www.americanheart.org/presenter.jhtml?identifier=3003999 by selecting either the “topic list” link or the “chronological list” link (No. KB-0110). To purchase additional reprints, call 843-216-2533 or e-mail .
Permissions: Multiple copies, modification, alteration, enhancement, and/or distribution of this document are not permitted without the express permission of the American Heart Association. Instructions for obtaining permission are located at http://www.americanheart.org/presenter.jhtml?identifier=4431. A link to the “Permission Request Form” appears on the right side of the page.
ACCF/AHA Task Force on Performance Measures
Frederick A. Masoudi, MD, MSPH, FACC, FAHA, Chair; Robert O. Bonow, MD, MACC, FAHA†††; Elizabeth DeLong, PhD; John P. Erwin III, MD, FACC; David C. Goff, Jr, MD, PhD, FAHA, FACP; Kathleen Grady, PhD, RN, FAHA, FAAN; Lee A. Green, MD, MPH; Paul A. Heidenreich, MD, FACC, FAHA; Kathy J. Jenkins, MD, MPH, FACC; Ann R. Loth, RN, MS, CNS; Eric D. Peterson, MD, MPH, FACC, FAHA; David M. Shahian, MD, FACC
- © 2010 American Heart Association, Inc.
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